Random Tips & Hints

Zen Broadband with IPv6 using FreeBSD ppp router

A little while ago, i switched broadband providers so that I could enjoy the greater speeds on FTTC (fibre-to-the-cabinet) technology. My existing ISP charged an insanely high amount for their unlimited package so I went through the hassle of renumbering my home network.

I chose to go with Zen broadband… I’ve used Zen in the past, and always been happy… plus they support IPv6 (of which I’m a big supporter)

So… here’s how to connect to Zen broadband (and possibly others) using FreeBSD as a router (via PPPoE) with the Zen provided DSL modem in passthrough mode.

Zen provide a Zyxel VMG1312-B10D DSL modem. First you need to change the modem into bridged mode. I won’t detail that here, there’s way too many documents online that show how to do it. (alternatively, use another modem in bridge mode… I couldn’t get a Draytek to bridge properly – so perhaps avoid that.)

On the FreeBSD router, you need a dedicated network card for running PPPoE – I added an intel gigabit card to my router, so my PPPoE interface is igb0

First, we need to load some kernel modules, so add to /boot/loader.conf:

NOTE: everything except the first “zen:” line is indented – wordpress has a habit of losing the indentation! Put your Zen-provided username and password in place of the capitalised placeholders above. Also, change ‘igb0’ to a different interface depending on your router configuration.

This will load the ‘zen’ profile in ‘ddial’ mode on boot. It disables NAT in the PPP daemon.

The above is enough to negotiate IPv4, and to start the IPv6 negotiation – but zen requires that you use SLAAC to obtain an IPv6 IP, so we need to create another file for this. This will run after connecting. Create the file /etc/ppp/ppp.linkup with the following contents: